For over 35 years, K&K Produce has been a leading supplier of fresh food in Ireland. As a member of the An Bord Bia Origin Green Scheme, Ireland’s food and drink sustainability programme, K&K Produce work with large fruit and vegetable growers based in Ireland and overseas to provide fresh potatoes, fruit and vegetables to the retail, food and wholesale markets.
Processing potatoes involves sourcing from third party suppliers, washing, grading and packaging. The washing process generates sludge which would ordinarily be disposed of by spreading on farmland. Since K&K Produce had no available land for spreading the sludge, the wash residue was concentrated in settling tanks and the sludge disposed of through a licensed waste management company.
In order to satisfy the An Bord Bia Origin Green requirements, the company commissioned Callaghan Engineering (CE) to review current European best practice for potato washing facilities. Having reviewed several potato washing facilities in the UK and in The Netherlands, CE devised a more sustainable approach based on a closed loop wash water recycling system. This approach solved the contradictory requirements of space constraints, planning and regulatory compliance.
The primary components of the system are a lamella separator to clarify the water and a belt press filter to recover the maximum possible amount of water from the sludge generated.
The output consists of a dry solid clay residue and recycled water. The entire system is computer controlled with variable speed motors to monitor and optimize the process while minimising energy consumption.
Water conservation was achieved through a closed loop cycle, providing a full recycled water exchange in the washer every hour. This reduced the metered water consumption in the facility by 100 cubic metres per week of operation.
This project delivered the first successfully commissioned potato washing facility incorporating a water recycling system in Ireland. The project demonstrates the commitment of K&K Produce to environmental sustainability, offering their customers environmentally friendly products, and qualifying for the An Bord Bia Origin Green accreditation.
The main benefits to K&K Produce have been:
- Compliance with the An Bord Bia Origin Green requirements.
- 100 m3 of fresh feed water saved per week.
- Wastewater from potato washing process eliminated.
- Wash water quality improvement with a potential benefit on the potatoes shelf life.
- The factory eliminated sludge management costs as the clay residue is pressed and dried, suitable for land spreading.